gevorgparsyan:
Thank you all for your responses. Actually I would like go back to the subject.
I haven't bought the display.
The problem is that someone might buy one of these items thinking that they could utilise it without the complete specifications and datasheet detailing how to drive it. In general, you require not only the display, but to purchase the correct driver IC at the same time.
gevorgparsyan:
The display supports 6 digits, 72 pins, 36 at each side. I searched for other 7-segment 6 digit displays, and there are many different of those with different number of pins. I wonder what is the difference between 72-pin and for example 36-pin 6-digit displays?
The difference is the number of pins!
It is entirely conjectural. The listing contains essentially no information whatsoever about the display. The pictures do not show it - not surprisingly as the seller has no idea what it is - in any form of operational state. There is no proof that it is actually a six digit display and in fact, its design suggests it is not or at least not just a six digit display.
A standard LCD has a single "backplane" pin and one pin per segment. If each digit has eight segments including decimal, that counts as 49 pins for six digits, does it not? 49 is neither 36 nor 72. If each digit had a separate backplane, then it would be 54 pins. Again, it does not match.
Sorry, what is advertised simply makes no sense and under the circumstances no-one here would consider it worth buying at such a ridiculous (high) price! Perhaps for a dollar it would be worth the risk and the trouble of working out the connections (which is not too difficult, but tedious).
gevorgparsyan:
Yet, the problem is not in the seller, as there are many other sellers who offer such displays.
And do they provide the complete specifications?
There are no doubt, no end of eBay sellers offering random junk, Occasionally it may have a value to a particular person who specifically recognises it as a part that they actually need or will treasure for sentimental reasons because they know what it is, even if the seller does not. That's fine, but that is far from the case here.